You can find some ad keywords recommend tool of Google,Yahoo. You can find many related words through this kind of tools. Then you'd have a brain storm or just judege by yourself to choose the primary and the second primary keywords.

I use google Adwords keyword tool. Write some articles and submit them to directories with keyword links pointing to your site, submit you site to directories, exchange links with quality sites that have the same topic or are in the same industry.

I'll suggest you Google keyword tool(Google Adwords). If you wants to rank up in SERP than you have to do strong and relevant SEO work for your website. You can do blog comments and posting, forums postings, article submissions, directory submission, classified ads and bookmarking for your site to rank up. But you always have to concern about relevancy. Google and other search engines only considers relevant seo work.

1) Google Adwords Keyword Tool is the best one for research keywords and choose the long tail keywords will bring more traffic for the website.
2) Quality Fresh Content & Quality Backlinks will help to rank better in the Google SERP.

what you need to understand is to know how to pick a right keyword for your website's niche. It is easy to search for a keyword but to decide on what should you use is the one thing that you need to understand. Plus a correct usage of your keyword in promoting your website. Don't just post or promote in a spammy way. Use keywords in posting or in every update you made on your social media sites.